The mammalian and avian hippocampus appears to grow in response to natural selection pressures for spatial cognition. The proposed research will investigate if the structural homolog to the hippocampus in lizards, the medial cortex, is necessary for place memory and grows in response to the ecological demands of active foraging. The performance of Cnemidophorous inornatus males with lesions of the medial cortex and dorsal cortex will be compared to sham operated animals. I will examine two pairs of congeneric species of lacertids that have different foraging styles. It is expected that the active foragers will have better place memory and a larger medial cortex volume than sit-and- wait predators. The study of the role of the medial cortex as a homologue to the hippocampus may provide more models for the analysis of memory and learning that may be useful for research relating to disorders involving hippocampal dysfunction including Alzheimer's, strokes, and accident- induced brain trauma. The molecular basis of memory via studies of long-term potentiation may also be studied using reptiles once we have a better understanding of the neural structures of learning and memory in this phyla.